The purpose of this study was to determine the effects of resistance training on endurance performance and selected muscle characteristics of female cyclists.

Endurance-trained, female cyclists, (N = 21; aged 18-42), were randomly assigned to either a resistance training (RT; N = 14) or a control group (CON; N = 7). Resistance training (twice per week) consisted of five sets to failure (2-8 RM) of parallel squats for 12 weeks. Ss were tested before and immediately after the resistance-training period. Ss completed an incremental cycle test to determine both lactate threshold (LT) and peak oxygen consumption (VO2). Endurance performance was assessed by average power output during a 1-hour cycle test (OHT). Leg strength was determined as each S's 1 RM concentric squat. Resting muscle was sampled by needle biopsy from the vastus lateralis muscle and analyzed for fiber type diameter, fiber type percentage, and the activities of 2-oxoglutarate dehydrogenase and phosphofructokinase enzymes.

After the resistance training program, there was a significant increase in 1 RM concentric squat strength for RT (35.9%) but not for CON (3.7%). However, there were no significant changes in OHT performance, LT, VO2, muscle fiber characteristics, or enzyme activities in either group.